--- tests/functions.sh.in | 17 ++++++++++++++++- tests/test-cache-max-size.sh | 18 +++--------------- tests/test-data-7E.sh | 8 ++------ tests/test-data-base64.sh | 12 ++++-------- tests/test-data-file.sh | 8 ++------ tests/test-data-raw.sh | 8 ++------ tests/test-eflags.sh | 13 +++++-------- tests/test-error0.sh | 6 +----- tests/test-error10.sh | 6 +----- tests/test-error100.sh | 6 +----- tests/test-full.sh | 8 ++------ tests/test-ip.sh | 21 ++++++--------------- tests/test-memory-largest-for-qemu.sh | 8 ++------ tests/test-memory-largest.sh | 8 ++------ tests/test-offset2.sh | 8 ++------ tests/test-parallel-file.sh | 10 ++-------- tests/test-parallel-nbd.sh | 10 ++-------- tests/test-partition1.sh | 22 ++++------------------ tests/test-partition2.sh | 6 +----- tests/test-partitioning1.sh | 8 ++------ tests/test-partitioning2.sh | 8 ++------ tests/test-partitioning4.sh | 6 +----- tests/test-partitioning5.sh | 8 ++------ tests/test-partitioning6.sh | 6 +----- tests/test-pattern-largest-for-qemu.sh | 8 ++------ tests/test-pattern-largest.sh | 8 ++------ tests/test-single.sh | 11 ++--------- tests/test-tls-psk.sh | 12 +++--------- tests/test-tls.sh | 12 +++--------- tests/test-truncate1.sh | 8 ++------ tests/test-truncate2.sh | 8 ++------ tests/test-truncate3.sh | 8 ++------ tests/test-zero.sh | 6 +----- 33 files changed, 87 insertions(+), 233 deletions(-) diff --git a/tests/functions.sh.in b/tests/functions.sh.in index 35647f7..289584a 100644 --- a/tests/functions.sh.in +++ b/tests/functions.sh.in @@ -1,7 +1,7 @@ # nbdkit # Common functions used by the tests. # @configure_input@ -# Copyright (C) 2017-2018 Red Hat Inc. +# Copyright (C) 2017-2019 Red Hat Inc. # All rights reserved. # # Redistribution and use in source and binary forms, with or without @@ -57,6 +57,21 @@ _run_cleanup_hooks () } trap _run_cleanup_hooks INT QUIT TERM EXIT ERR +# requires program [args] +# +# Check that ‘program [args]’ works. If not, skip the test. +# For example to check that qemu-img is available, do: +# +# requires qemu-img --version +requires () +{ + ( "$@" ) </dev/null >/dev/null 2>&1 || { + echo "$0: ‘$*’ failed with error code $?" + echo "$0: test prerequisite is missing or not working" + exit 77 + } +} + # start_nbdkit -P pidfile args... # # Run nbdkit with args and wait for it to start up. If it fails to diff --git a/tests/test-cache-max-size.sh b/tests/test-cache-max-size.sh index f7e743a..8cb5ad1 100755 --- a/tests/test-cache-max-size.sh +++ b/tests/test-cache-max-size.sh @@ -36,22 +36,10 @@ set -e set -x # Check that this is a Linux-like system supporting /proc/$pid/fd. -if ! test -d /proc/self/fd; then - echo "$0: not a Linux-like system supporting /proc/\$pid/fd" - exit 77 -fi - -# Test that qemu-io works -if ! qemu-io --help >/dev/null; then - echo "$0: missing or broken qemu-io" - exit 77 -fi - +requires test -d /proc/self/fd +requires qemu-io --version # Need the stat command from coreutils. -if ! stat --version >/dev/null; then - echo "$0: missing or broken stat command" - exit 77 -fi +requires stat --version d=cache-max-size.d rm -rf $d diff --git a/tests/test-data-7E.sh b/tests/test-data-7E.sh index e27984f..2e48e1b 100755 --- a/tests/test-data-7E.sh +++ b/tests/test-data-7E.sh @@ -38,16 +38,12 @@ source ./functions.sh set -e set -x +requires qemu-io --version + files="data-7E.out data-7E.pid data-7E.sock" rm -f $files cleanup_fn rm -f $files -# Test that qemu-io works -if ! qemu-io --help >/dev/null; then - echo "$0: missing or broken qemu-io" - exit 77 -fi - # Run nbdkit. start_nbdkit -P data-7E.pid -U data-7E.sock --export= \ --filter=partition \ diff --git a/tests/test-data-base64.sh b/tests/test-data-base64.sh index cc53edf..b755557 100755 --- a/tests/test-data-base64.sh +++ b/tests/test-data-base64.sh @@ -37,9 +37,7 @@ source ./functions.sh set -e set -x -files="data-base64.out data-base64.pid data-base64.sock" -rm -f $files -cleanup_fn rm -f $files +requires qemu-io --version # Test if the base64 parameter is supported in this build. if ! nbdkit data --dump-plugin | grep -sq "data_base64=yes"; then @@ -47,11 +45,9 @@ if ! nbdkit data --dump-plugin | grep -sq "data_base64=yes"; then exit 77 fi -# Test that qemu-io works -if ! qemu-io --help >/dev/null; then - echo "$0: missing or broken qemu-io" - exit 77 -fi +files="data-base64.out data-base64.pid data-base64.sock" +rm -f $files +cleanup_fn rm -f $files # Run nbdkit. start_nbdkit -P data-base64.pid -U data-base64.sock \ diff --git a/tests/test-data-file.sh b/tests/test-data-file.sh index ba7288c..c6792e7 100755 --- a/tests/test-data-file.sh +++ b/tests/test-data-file.sh @@ -37,16 +37,12 @@ source ./functions.sh set -e set -x +requires qemu-io --version + files="data-file.out data-file.pid data-file.sock data-hello.txt" rm -f $files cleanup_fn rm -f $files -# Test that qemu-io works -if ! qemu-io --help >/dev/null; then - echo "$0: missing or broken qemu-io" - exit 77 -fi - rm -f data-hello.txt for i in {0..1000}; do echo -n "hello " >> data-hello.txt diff --git a/tests/test-data-raw.sh b/tests/test-data-raw.sh index 555b77c..c71afbf 100755 --- a/tests/test-data-raw.sh +++ b/tests/test-data-raw.sh @@ -37,16 +37,12 @@ source ./functions.sh set -e set -x +requires qemu-io --version + files="data-raw.out data-raw.pid data-raw.sock" rm -f $files cleanup_fn rm -f $files -# Test that qemu-io works -if ! qemu-io --help >/dev/null; then - echo "$0: missing or broken qemu-io" - exit 77 -fi - # Run nbdkit. start_nbdkit -P data-raw.pid -U data-raw.sock --export "" \ data raw=123 size=512 diff --git a/tests/test-eflags.sh b/tests/test-eflags.sh index 5ac5e9e..41793e8 100755 --- a/tests/test-eflags.sh +++ b/tests/test-eflags.sh @@ -45,16 +45,13 @@ source ./functions.sh set -e -if ! socat -h >/dev/null; then - echo "$0: 'socat' command not available" - exit 77 -fi +requires socat -h # Check 'od' command exists. -if ! od </dev/null >/dev/null; then - echo "$0: 'od' command not available" - exit 77 -fi +# +# Note that requires redirects stdin/stdout to /dev/null which +# prevents od from hanging in this test. +requires od files="eflags.out" rm -f $files diff --git a/tests/test-error0.sh b/tests/test-error0.sh index 93170a9..96a221c 100755 --- a/tests/test-error0.sh +++ b/tests/test-error0.sh @@ -35,11 +35,7 @@ source ./functions.sh set -e set -x -# Test that qemu-io works -if ! qemu-io --help >/dev/null; then - echo "$0: missing or broken qemu-io" - exit 77 -fi +requires qemu-io --version files="error0.sock error0.pid" rm -f $files diff --git a/tests/test-error10.sh b/tests/test-error10.sh index 278bae4..d5ab1d4 100755 --- a/tests/test-error10.sh +++ b/tests/test-error10.sh @@ -35,11 +35,7 @@ source ./functions.sh set -e set -x -# Test that qemu-io works -if ! qemu-io --help >/dev/null; then - echo "$0: missing or broken qemu-io" - exit 77 -fi +requires qemu-io --version files="error10.sock error10.pid" rm -f $files diff --git a/tests/test-error100.sh b/tests/test-error100.sh index 997de9d..1979717 100755 --- a/tests/test-error100.sh +++ b/tests/test-error100.sh @@ -35,11 +35,7 @@ source ./functions.sh set -e set -x -# Test that qemu-io works -if ! qemu-io --help >/dev/null; then - echo "$0: missing or broken qemu-io" - exit 77 -fi +requires qemu-io --version files="error100.sock error100.pid" rm -f $files diff --git a/tests/test-full.sh b/tests/test-full.sh index 171d716..71d9c7c 100755 --- a/tests/test-full.sh +++ b/tests/test-full.sh @@ -37,16 +37,12 @@ source ./functions.sh set -e +requires qemu-io --version + files="full.pid full.sock full.out" rm -f $files cleanup_fn rm -f $files -# Test that qemu-io works -if ! qemu-io --help >/dev/null; then - echo "$0: missing or broken qemu-io" - exit 77 -fi - # Run nbdkit with the full plugin. start_nbdkit -P full.pid -U full.sock full size=1M diff --git a/tests/test-ip.sh b/tests/test-ip.sh index d7d5323..f5dcd87 100755 --- a/tests/test-ip.sh +++ b/tests/test-ip.sh @@ -37,26 +37,17 @@ source ./functions.sh set -e -rm -f ip.pid ipv4.out ipv6.out -cleanup_fn rm -f ip.pid ipv4.out ipv6.out +requires ss --version +requires ip -V +requires qemu-img --version -# Don't fail if certain commands aren't available. -if ! ss --version; then - echo "$0: 'ss' command not available" - exit 77 -fi -if ! command -v qemu-img; then - echo "$0: 'qemu-img' command not available" - exit 77 -fi if ! qemu-img --help | grep -- --image-opts; then echo "$0: 'qemu-img' command does not have the --image-opts option" exit 77 fi -if ! ip -V; then - echo "$0: 'ip' command not available" - exit 77 -fi + +rm -f ip.pid ipv4.out ipv6.out +cleanup_fn rm -f ip.pid ipv4.out ipv6.out # Find an unused port to listen on. for port in {49152..65535}; do diff --git a/tests/test-memory-largest-for-qemu.sh b/tests/test-memory-largest-for-qemu.sh index 2b56f30..a89fd0d 100755 --- a/tests/test-memory-largest-for-qemu.sh +++ b/tests/test-memory-largest-for-qemu.sh @@ -37,16 +37,12 @@ source ./functions.sh set -e +requires qemu-io --version + files="memory-largest-for-qemu.out memory-largest-for-qemu.pid memory-largest-for-qemu.sock" rm -f $files cleanup_fn rm -f $files -# Test that qemu-io works -if ! qemu-io --help >/dev/null; then - echo "$0: missing or broken qemu-io" - exit 77 -fi - # Run nbdkit with memory plugin. # size = (2^63-1) & ~511 which is the largest supported by qemu. start_nbdkit -P memory-largest-for-qemu.pid -U memory-largest-for-qemu.sock \ diff --git a/tests/test-memory-largest.sh b/tests/test-memory-largest.sh index a6c269e..154b331 100755 --- a/tests/test-memory-largest.sh +++ b/tests/test-memory-largest.sh @@ -37,16 +37,12 @@ source ./functions.sh set -e +requires qemu-io --version + files="memory-largest.out memory-largest.pid memory-largest.sock" rm -f $files cleanup_fn rm -f $files -# Test that qemu-io works -if ! qemu-io --help >/dev/null; then - echo "$0: missing or broken qemu-io" - exit 77 -fi - # Run nbdkit with memory plugin. # size = 2^63-1 start_nbdkit -P memory-largest.pid -U memory-largest.sock \ diff --git a/tests/test-offset2.sh b/tests/test-offset2.sh index 4e1ef2b..a958f62 100755 --- a/tests/test-offset2.sh +++ b/tests/test-offset2.sh @@ -37,16 +37,12 @@ source ./functions.sh set -e set -x +requires qemu-io --version + files="offset2.out offset2.pid offset2.sock" rm -f $files cleanup_fn rm -f $files -# Test that qemu-io works -if ! qemu-io --help >/dev/null; then - echo "$0: missing or broken qemu-io" - exit 77 -fi - # Run nbdkit with pattern plugin and offset filter in front. # 8070450532247927809 = 7E - 1023 start_nbdkit -P offset2.pid -U offset2.sock \ diff --git a/tests/test-parallel-file.sh b/tests/test-parallel-file.sh index 1d27f93..0fabd4f 100755 --- a/tests/test-parallel-file.sh +++ b/tests/test-parallel-file.sh @@ -34,14 +34,8 @@ source ./functions.sh # Check file-data was created by Makefile and qemu-io exists. -if ! test -f file-data; then - echo "$0: missing file-data" - exit 77 -fi -if ! qemu-io --version; then - echo "$0: missing qemu-io" - exit 77 -fi +requires test -f file-data +requires qemu-io --version cleanup_fn rm -f test-parallel-file.data test-parallel-file.out diff --git a/tests/test-parallel-nbd.sh b/tests/test-parallel-nbd.sh index e4a2352..cb81ec9 100755 --- a/tests/test-parallel-nbd.sh +++ b/tests/test-parallel-nbd.sh @@ -34,14 +34,8 @@ source ./functions.sh # Check file-data was created by Makefile and qemu-io exists. -if ! test -f file-data; then - echo "$0: missing file-data" - exit 77 -fi -if ! qemu-io --version; then - echo "$0: missing qemu-io" - exit 77 -fi +requires test -f file-data +requires qemu-io --version # We require --exit-with-parent to work ( nbdkit --exit-with-parent --help ) >/dev/null 2>&1 || diff --git a/tests/test-partition1.sh b/tests/test-partition1.sh index 1bb0240..50d4087 100755 --- a/tests/test-partition1.sh +++ b/tests/test-partition1.sh @@ -35,29 +35,15 @@ source ./functions.sh set -e set -x +requires sfdisk --help +requires test -r /dev/urandom +requires qemu-img --version + d="partition1.d" rm -rf $d cleanup_fn rm -rf $d mkdir $d -# Test that sfdisk is available and working. -if ! sfdisk --help >/dev/null; then - echo "$0: missing or broken sfdisk" - exit 77 -fi - -# Test that /dev/urandom exists and can be read. -if ! test -r /dev/urandom; then - echo "$0: mising or unreadable /dev/urandom" - exit 77 -fi - -# Test that qemu-img is available and working. -if ! qemu-img --help >/dev/null; then - echo "$0: missing or broken qemu-img" - exit 77 -fi - test () { label=$1 diff --git a/tests/test-partition2.sh b/tests/test-partition2.sh index 71bac55..4678a5c 100755 --- a/tests/test-partition2.sh +++ b/tests/test-partition2.sh @@ -35,11 +35,7 @@ source ./functions.sh set -e set -x -# Test that qemu-img is available and working. -if ! qemu-img --help >/dev/null; then - echo "$0: missing or broken qemu-img" - exit 77 -fi +requires qemu-img --version files="partition2.log" rm -f $files diff --git a/tests/test-partitioning1.sh b/tests/test-partitioning1.sh index f705dc8..f0c779d 100755 --- a/tests/test-partitioning1.sh +++ b/tests/test-partitioning1.sh @@ -39,16 +39,12 @@ source ./functions.sh set -e set -x +requires qemu-img --version + files="partitioning1.out partitioning1-p1 partitioning1-p2 partitioning1-p3 partitioning1-p4 partitioning1-p5 partitioning1-p6" rm -f $files cleanup_fn rm -f $files -# Test that qemu-img works -if ! qemu-img --help >/dev/null; then - echo "$0: missing or broken qemu-img" - exit 77 -fi - # Create some odd-sized partitions. These exist to test alignment and # padding. truncate -s 1 partitioning1-p1 diff --git a/tests/test-partitioning2.sh b/tests/test-partitioning2.sh index 411f392..9f2df11 100755 --- a/tests/test-partitioning2.sh +++ b/tests/test-partitioning2.sh @@ -40,16 +40,12 @@ source ./functions.sh set -e set -x +requires mke2fs -V + files="partitioning2.pid partitioning2.sock partitioning2.fs partitioning2.p1 partitioning2.p3" rm -f $files cleanup_fn rm -f $files -# Test that mke2fs works -if ! mke2fs -V; then - echo "$0: missing or broken mke2fs" - exit 77 -fi - # Create partitions before and after. truncate -s 1 partitioning2.p1 truncate -s 10M partitioning2.p3 diff --git a/tests/test-partitioning4.sh b/tests/test-partitioning4.sh index 8988a5c..8c9a93e 100755 --- a/tests/test-partitioning4.sh +++ b/tests/test-partitioning4.sh @@ -43,11 +43,7 @@ source ./functions.sh set -e set -x -# Test that qemu-img works -if ! qemu-img --help >/dev/null; then - echo "$0: missing or broken qemu-img" - exit 77 -fi +requires qemu-img --version d=partitioning4.d rm -rf $d diff --git a/tests/test-partitioning5.sh b/tests/test-partitioning5.sh index b4cb6bf..feeb738 100755 --- a/tests/test-partitioning5.sh +++ b/tests/test-partitioning5.sh @@ -41,18 +41,14 @@ source ./functions.sh set -e set -x +requires mke2fs -V + files="partitioning5.pid partitioning5.sock partitioning5.fs partitioning5.p1 partitioning5.p2 partitioning5.p3 partitioning5.p5 partitioning5.p6 partitioning5.p7 partitioning5.p8 partitioning5.p9 partitioning5.p10 partitioning5.p11 partitioning5.p13" rm -f $files cleanup_fn rm -f $files -# Test that mke2fs works -if ! mke2fs -V; then - echo "$0: missing or broken mke2fs" - exit 77 -fi - # Create partitions before and after. truncate -s 1 partitioning5.p1 truncate -s 10M partitioning5.p2 diff --git a/tests/test-partitioning6.sh b/tests/test-partitioning6.sh index 6dbb215..400bd8e 100755 --- a/tests/test-partitioning6.sh +++ b/tests/test-partitioning6.sh @@ -43,11 +43,7 @@ source ./functions.sh set -e set -x -# Test that qemu-img works -if ! qemu-img --help >/dev/null; then - echo "$0: missing or broken qemu-img" - exit 77 -fi +requires qemu-img --version d=partitioning6.d rm -rf $d diff --git a/tests/test-pattern-largest-for-qemu.sh b/tests/test-pattern-largest-for-qemu.sh index 1883fe6..93cc1b7 100755 --- a/tests/test-pattern-largest-for-qemu.sh +++ b/tests/test-pattern-largest-for-qemu.sh @@ -37,16 +37,12 @@ source ./functions.sh set -e +requires qemu-io --version + files="pattern-largest-for-qemu.out pattern-largest-for-qemu.pid pattern-largest-for-qemu.sock" rm -f $files cleanup_fn rm -f $files -# Test that qemu-io works -if ! qemu-io --help >/dev/null; then - echo "$0: missing or broken qemu-io" - exit 77 -fi - # Run nbdkit with pattern plugin. # size = (2^63-1) & ~511 which is the largest supported by qemu. start_nbdkit -P pattern-largest-for-qemu.pid -U pattern-largest-for-qemu.sock \ diff --git a/tests/test-pattern-largest.sh b/tests/test-pattern-largest.sh index de5e1d7..0b6d272 100755 --- a/tests/test-pattern-largest.sh +++ b/tests/test-pattern-largest.sh @@ -37,16 +37,12 @@ source ./functions.sh set -e +requires qemu-io --version + files="pattern-largest.out pattern-largest.pid pattern-largest.sock" rm -f $files cleanup_fn rm -f $files -# Test that qemu-io works -if ! qemu-io --help >/dev/null; then - echo "$0: missing or broken qemu-io" - exit 77 -fi - # Run nbdkit with pattern plugin. # size = 2^63-1 start_nbdkit -P pattern-largest.pid -U pattern-largest.sock \ diff --git a/tests/test-single.sh b/tests/test-single.sh index 3739df2..3462d3d 100755 --- a/tests/test-single.sh +++ b/tests/test-single.sh @@ -35,15 +35,8 @@ source ./functions.sh set -e set -x -if ! socat -h; then - echo "$0: 'socat' command not available" - exit 77 -fi - -if ! qemu-img --help >/dev/null; then - echo "$0: 'qemu-img' command not available" - exit 77 -fi +requires socat -h +requires qemu-img --version files="single.sock single.disk" rm -f $files diff --git a/tests/test-tls-psk.sh b/tests/test-tls-psk.sh index 819d63d..bc4140f 100755 --- a/tests/test-tls-psk.sh +++ b/tests/test-tls-psk.sh @@ -35,15 +35,9 @@ source ./functions.sh set -e set -x -# Don't fail if certain commands aren't available. -if ! ss --version; then - echo "$0: 'ss' command not available" - exit 77 -fi -if ! command -v qemu-img > /dev/null; then - echo "$0: 'qemu-img' command not available" - exit 77 -fi +requires ss --version +requires qemu-img --version + if ! qemu-img --help | grep -- --object; then echo "$0: 'qemu-img' command does not have the --object option" exit 77 diff --git a/tests/test-tls.sh b/tests/test-tls.sh index 114ea35..9f94ba1 100755 --- a/tests/test-tls.sh +++ b/tests/test-tls.sh @@ -35,15 +35,9 @@ source ./functions.sh set -e set -x -# Don't fail if certain commands aren't available. -if ! ss --version; then - echo "$0: 'ss' command not available" - exit 77 -fi -if ! command -v qemu-img > /dev/null; then - echo "$0: 'qemu-img' command not available" - exit 77 -fi +requires ss --version +requires qemu-img --version + if ! qemu-img --help | grep -- --object; then echo "$0: 'qemu-img' command does not have the --object option" exit 77 diff --git a/tests/test-truncate1.sh b/tests/test-truncate1.sh index eb02a69..e09415a 100755 --- a/tests/test-truncate1.sh +++ b/tests/test-truncate1.sh @@ -37,16 +37,12 @@ source ./functions.sh set -e set -x +requires qemu-io --version + files="truncate1.out truncate1.pid truncate1.sock" rm -f $files cleanup_fn rm -f $files -# Test that qemu-io works -if ! qemu-io --help >/dev/null; then - echo "$0: missing or broken qemu-io" - exit 77 -fi - # Run nbdkit with pattern plugin and truncate filter in front. start_nbdkit -P truncate1.pid -U truncate1.sock \ --filter=truncate \ diff --git a/tests/test-truncate2.sh b/tests/test-truncate2.sh index 4a3a89e..f290f29 100755 --- a/tests/test-truncate2.sh +++ b/tests/test-truncate2.sh @@ -37,16 +37,12 @@ source ./functions.sh set -e set -x +requires qemu-io --version + files="truncate2.out truncate2.pid truncate2.sock" rm -f $files cleanup_fn rm -f $files -# Test that qemu-io works -if ! qemu-io --help >/dev/null; then - echo "$0: missing or broken qemu-io" - exit 77 -fi - # Run nbdkit with pattern plugin and truncate filter in front. start_nbdkit -P truncate2.pid -U truncate2.sock \ --filter=truncate \ diff --git a/tests/test-truncate3.sh b/tests/test-truncate3.sh index 0ff1cbe..de44a17 100755 --- a/tests/test-truncate3.sh +++ b/tests/test-truncate3.sh @@ -38,16 +38,12 @@ source ./functions.sh set -e set -x +requires qemu-img --version + files="truncate3.out truncate3.pid truncate3.sock" rm -f $files cleanup_fn rm -f $files -# Test that qemu-img works -if ! qemu-img --help >/dev/null; then - echo "$0: missing or broken qemu-img" - exit 77 -fi - # Run nbdkit with pattern plugin and truncate filter in front. start_nbdkit -P truncate3.pid -U truncate3.sock \ --filter=truncate \ diff --git a/tests/test-zero.sh b/tests/test-zero.sh index 3c3a0ca..2bd4a48 100755 --- a/tests/test-zero.sh +++ b/tests/test-zero.sh @@ -35,11 +35,7 @@ source ./functions.sh set -x set -e -# Check qemu-img exists. -if ! qemu-img --version; then - echo "$0: missing qemu-img" - exit 77 -fi +requires qemu-img --version files="test-zero.out" rm -f $files -- 2.20.1

On Wed, Jan 23, 2019 at 10:02:18AM -0600, Eric Blake wrote: Yes - as you can see I didn't convert the old test, it's still there. However I will try your variation to see if that works instead. We had a problem on FreeBSD where truncate --size does not work (their binary only understands truncate -s). That was fixed by commit f62e3712428. Do you know what platforms would lack truncate entirely? Rich. -- Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones Read my programming and virtualization blog: http://rwmj.wordpress.com libguestfs lets you edit virtual machines. Supports shell scripting, bindings from many languages. http://libguestfs.org